Dynamic Nuclear Polarization Provides New Insights into Chromophore Structure in Phytochrome Photoreceptors.
Dynamic Nuclear Polarization Provides New Insights into Chromophore Structure in Phytochrome Photoreceptors.
复制标题
DOI：
10.1002/anie.201608119
复制
发表时间：
2016-11
影响因子：
--
通讯作者：
Daniel Stöppler;Chen Song;B. van Rossum;Michel-Andreas Geiger;C. Lang;M. Mroginski;A. P. Jagtap;S. Sigurdsson;J. Matysik;J. Hughes;H. Oschkinat
中科院分区：
文献类型：
--
作者：
Daniel Stöppler;Chen Song;B. van Rossum;Michel-Andreas Geiger;C. Lang;M. Mroginski;A. P. Jagtap;S. Sigurdsson;J. Matysik;J. Hughes;H. Oschkinat
光敏色素是一种红色/远红色的光致变色光感受器，在高等植物中起主要的发育调节作用，从而控制约20%的基因转录。光诱导的十亿蛋白发色团异构化导致蛋白质结构的大重排，因此质子化动力学和电荷分布的作用是特别感兴趣的。为了帮助揭示其内在机制，我们展示了蓝藻光敏色素Cph1功能感觉模块的二维动态核极化（DNP）增强固态魔角旋转（MAS） NMR谱。为此，吡咯环氮信号被明确地分配，使我们能够定位藻蓝胆素（PCB）发色团的正电荷。为了帮助分析质子交换途径，还确定了PCB环氮原子和功能相关的H2 O分子的接近度。我们的研究证明了DNP在生物固态MAS核磁共振光谱中的价值。
Phytochromes are red/far-red photochromic photoreceptors acting as master regulators of development in higher plants, thereby controlling transcription of about 20 % of their genes. Light-induced isomerization of the bilin chromophore leads to large rearrangements in protein structure, whereby the role of protonation dynamics and charge distribution is of particular interest. To help unravel the inherent mechanisms, we present two-dimensional dynamic nuclear polarization (DNP) enhanced solid-state magic-angle spinning (MAS) NMR spectra of the functional sensory module of the cyanobacterial phytochrome Cph1. To this end, the pyrrole ring nitrogen signals were assigned unequivocally, enabling us to locate the positive charge of the phycocyanobilin (PCB) chromophore. To help analyze proton exchange pathways, the proximity of PCB ring nitrogen atoms and functionally relevant H2 O molecules was also determined. Our study demonstrates the value of DNP in biological solid-state MAS NMR spectroscopy.